I have many Filipino employees over the years in the US and in call centers in Manila. We were on the Carnival Splendor in 2019 and our three waiters were all Filipinos. I jokingly asked the head waiter, "what night will we have adobo?" which is the national dish of the Philippines. He laughed.
On the last night of the cruise, he said, "I have something special for you." He brought my wife and I a bowl of chicken adobo which was on the crew mess that night. It wasn't presented with the same flair as the other dishes but it was quite good.
It has been my experience in that you can generally get just about anything you want if you ask for it ahead of time.
By the way, the MDR food on the Carnival Splendor was quite excellent.